Insole and upper are ready to be stitched together, but we need to add a welt to our list of materials. A welt is a leather rim that will be sewn around the upper and to which the sole is attached. Welt stitching effectively bonds the insole, lining, stiffener, upper and welt into a robust yet flexible item. In this respect, handmade welt stitching guarantees a truly timeless shoe, as it can be repaired over and over again.